Wheelchair lifting devices to raise and lower wheelchairs from a surface, such as the ground, to a door of a motor vehicle, such as a van or bus, have been used in the past. However, all of the prior art wheelchair lifting devices have heretofore been large and bulky and required installation with components either inside the compartment of the motor vehicle, or underneath the frame of the motor vehicle.
Accordingly, the prior art wheelchair lifting devices have suffered from several disadvantages. For example, lifting devices within the motor vehicle compartment have occupied usable space within the compartment of the motor vehicle. Lifting devices located underneath the frame of the motor vehicle have been susceptible to damage from stones or dirt during operation of the motor vehicle or being struck by the road surface when a speed bump or pothole is driven over.
Also, many of the prior art devices utilize sensors to detect when the platform of a wheelchair lifting device is in the proper position. Unfortunately, these sensors can become damaged or, if they rely on optical sensing, the optical sensors can become obscured so that they no longer operate. This is particularly troublesome in wheelchair lifting devices which are located underneath the frame of a motor vehicle, and therefore exposed to the elements. In addition, in colder climates, wheelchair lifting devices that are located underneath the frame of a vehicle are exposed to extremely low temperatures, such that either the lifting device, or the sensors, no longer operate.
Accordingly, there is a need in the art for an improved wheelchair lifting device which can be efficiently installed in a motor vehicle without having portions exposed to the elements and the road surface underneath the frame, or, having portions occupying usable space within the interior of the motor vehicle. Also, there is a need in the art for a wheelchair lifting device that is compact so that it can be installed in narrow locations.